Mechanically driven medication delivery patch

ABSTRACT

A medication delivery patch that is applied to the skin and activated to deliver a medication or other fluid into or through the skin. The patch may be completely mechanically driven, with no electronic components, for low cost, safety, and reliability. Pressing an activation button may set in motion a sequence of mechanical events that result in a needle exiting the patch into the skin of the user, and flow of fluid from an internal pouch in the patch into the user. When delivery is complete, another sequence of mechanical events may occur to retract the needle from the skin and stop the flow of fluid, and to show a visible indicator that delivery is complete. The patch may contain a fluid channel, such as a microfluidic channel, that controls the rate and time of delivery; this channel can be configured or selected for different medications or use cases.

BACKGROUND OF THE INVENTION Field of the Invention

One or more embodiments of the invention are related to the field ofmedication delivery devices. More particularly, but not by way oflimitation, one or more embodiments of the invention enable amechanically driven medication delivery patch.

Description of the Related Art

Wearable drug delivery devices known in the art use electronic controlsand electrically powered motorized pumps and valves. Some of thesedevices provide Bluetooth connectivity and control interfaces via mobilephones. While these devices provide significant capabilities, they aretypically expensive because of their sophisticated components anddifficult to utilize. In addition, their reliance on electronics andelectrical power may reduce device reliability and longevity.

Some wearable drug delivery devices without electronic components areknown in the art but they present problems and challenges in certainapplications. The device described in United States Patent PublicationUS20200384195A1 (“Moeller”) uses osmotic pressure to drive medicationfrom the patch to the needle in the user's skin; therefore it is notpurely mechanical. This device contains a pre-filled cartridgecontaining the medication. The device described in United States PatentPublication US20130123709A1 (“Carter”) is manually actuated by a user;the user pushes on actuator buttons to drive medication from the deviceinto the needle. This device is intended for self-administration of ashort bolus dose of insulin. The user fills the device periodically froma syringe.

There is a need for wearable drug delivery devices that workmechanically and that provide options for either short-term bolusdelivery or infusion over an extended period. There is a need formechanical wearable devices that can be either factory-filled or filledat the point of distribution such as at a pharmacy.

For at least the reasons described above there is a need for amechanically driven medication delivery patch with added flexibility inapplication. There are several other embodiments and features that arenovel and disclosed in the specification that will become apparent asthe device operation is described.

BRIEF SUMMARY OF THE INVENTION

One or more embodiments described in the specification are related to amechanically driven medication delivery patch. The patch may be placedon the skin and upon activation it may extend a needle into the skin anddeliver a contained medication or other fluid to the user, using storedmechanical energy and mechanical force.

One or more embodiments of the invention may include a patch with abottom surface, a top cover, and a pouch between the top cover and thebottom surface that is configured to contain fluid to be delivered to auser. The bottom surface of the patch may be configured to be attachedto the user's skin. There may be an activation button or otheractivation input. The activation button may be accessible through thetop cover. The patch may include a wedge that moves after activationfrom an initial position to an end-of-delivery position, and then fromthe end-of-delivery position to an end-of-travel position. The wedge maybe held in its initial position by a latch prior to activation. A forceelement may apply force to the wedge to cause it to move. The wedgeapplies pressure to the fluid in the pouch as it moves between theinitial position and the end-of-delivery position. In one or moreembodiments, the wedge may be any type of element that applies pressureto the fluid in the pouch; for example, it may be a roller that rollsacross the pouch. The patch may also include a needle sled with a pouchneedle configured to penetrate a pouch septum that is in contact withthe fluid in the pouch, a skin needle configured to penetrate the user'sskin, and a fluid channel that couples the interior of the pouch needleand the interior of the skin needle. The needle sled may be configuredto move between a retracted position and a deployed position. A needlesled latch may hold the needle sled latch in the retracted position. Aneedle sled force element may apply force to the needle sled to cause itto move to the deployed position and to cause the pouch needle topenetrate the pouch septum, the skin needle to penetrate the user'sskin, and fluid to flow from the pouch through the pouch needle, throughthe fluid channel, and through the skin needle into the user. When theactivation button is pressed, the wedge latch may be released, allowingthe wedge to move from its initial position, and the needle sled latchmay be released, allowing the needle sled to move to its deployedposition. When the wedge reaches its end-of-delivery position, the wedgemay apply force to the needle sled to move the needle sled towards itsretracted position, and to retract the pouch needle from the pouchseptum and retract the skin needle from the user's skin and into theinterior of the patch.

In one or more embodiments, the patch may contain no electroniccomponents.

In one or more embodiments, the pouch may include a flexible material.

One or more embodiments may have a plate between the wedge and thepouch; the wedge may apply force to the plate and the plate may transferthis force to the pouch to apply pressure to the enclosed fluid.

One or more embodiments may have a fill port coupled by a fill channelto the pouch, and a fill septum that closes the fill port and isconfigured to be penetrated by a fill needle to fill the pouch withfluid.

One or more embodiments may have a delivery complete indicator thatprovides a visual indication that the wedge has reached itsend-of-travel position. In one or more embodiments the top cover of thepatch may have a window through which the delivery complete indicator isvisible when the wedge reaches its end-of-travel position. The deliverycomplete indicator may be coupled to or integrated into the wedge.

In one or more embodiments, the fluid channel in the needle sled mayhave shape, length, diameter, materials, valves, or flow restrictors, orany combination thereof, to provide a desired rate of delivery of thefluid to the user over a desired time period between the start time whenthe activation button is pressed and a finish time when the wedgereaches its end-of-travel position. In one or more embodiments, thefluid channel may include a microfluidic channel. For example, in one ormore embodiments one or more of the shape, length, diameter, valves, andflow restrictors of the fluid channel may be configured to select adesired time period in a range between 10 seconds and 7 days.

Illustrative force elements that may be used in one or more embodimentsmay include springs. For example, the wedge force element may includeone or more wedge springs, and the needle sled force element may includeone or more needle sled springs.

In one or more embodiments, the activation button may have one or moreactivation button extensions that extend into the interior of the patchto contact the wedge latch when the button is pressed, applying force tothe wedge latch to release it.

In one or more embodiments, the wedge may be configured to contact aneedle sled release element that is coupled to the needle sled latch,and to transmit a portion of the force applied by the wedge forceelement to the needle sled release element to release the needle sledlatch. For example, when the wedge contacts the needle sled releaseelement, the needle sled release element may pivot to release the needlesled latch.

One or more embodiments may have a needle sled push carriage that iscoupled to the needle sled force element and that is releasably coupledto the needle sled. This carriage may be configured to transmit forcefrom the needle sled force element to the needle sled. In one or moreembodiments the needle sled push carriage may be configured to detachfrom the needle sled when the needle sled reaches its deployed position.For example, the patch may have one or more carriage release elementsconfigured to contact one or more portions of the needle sled pushcarriage when the needle sled reaches its deployed position and todecouple the needle sled push carriage from the needle sled.

In one or more embodiments the gauge of the pouch needle may be between18 gauge and 27 gauge, inclusive and the gauge of the skin needle may bebetween 25 gauge and 34 gauge inclusive.

One or more embodiments may have a curved channel through which the skinneedle travels when the needle sled moves from the retracted position tothe delivery position. This channel may cause the skin needle to changeorientation from substantially parallel to the skin in the retractedposition to non-parallel with the skin in the deployed position. Whenthe needle sled is in the deployed position, the angle between the skinand the skin needle may be greater than or equal to 45 degrees and lessthen 90 degrees in one or more embodiments.

One or more embodiments may have a feature or features that prevent theneedle sled from moving prior to user activation of the patch; this mayprevent accidental movement due to shock or vibration.

One or more embodiments may have a feature or features that prevent theactivation button from firing accidentally (prior to the user pressingthe button) due to shock or vibration.

One or more embodiments may incorporate a hydrophobic vent to vent airfrom the drug container as well as a portion of the fluid pathway.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the inventionwill be more apparent from the following more particular descriptionthereof, presented in conjunction with the following drawings wherein:

FIG. 1A shows a top view of an embodiment of a mechanically drivenmedication delivery patch prior to use.

FIG. 1B shows the embodiment of FIG. 1A with the safety cover removed toshow the activation button.

FIG. 1C shows a bottom view of the embodiment of FIG. 1B.

FIG. 2 shows illustrative use of the embodiment shown in FIGS. 1A and1B: the patch is placed on a user's skin, the safety cover is removed,and an activation button is pressed to start delivery of the medicationin the patch to or through the skin of the user.

FIG. 3 shows the embodiment of FIG. 1A with the top cover and activationbutton removed to show the internal components.

FIG. 4A shows the filled medication pouch of the embodiment of FIG. 1,with a wedge that presses on a plate to apply pressure to the pouch asthe wedge moves along the plate.

FIGS. 4B and 4C show side views of two other embodiments of a wedge.

FIG. 5 shows a closeup view of the activation button, the wedge latchthat holds the wedge in place prior to activation, and the wedge forceelements that push the wedge across the medication pouch.

FIGS. 6A, 6B, and 6C show a mechanism that may be used to release aneedle sled that connects and deploys pouch and skin needles when thewedge begins to move after activation. FIG. 6A shows the wedge andneedle sled latch prior to activation; FIG. 6B shows a different view ofthese elements to illustrate how the wedge pivots the latch, and FIG. 6Cshows the needle sled latch in the released position.

FIG. 7A shows an illustrative needle sled prior to activation, in itsretracted position.

FIG. 7B shows the needle sled in its deployed position, with the pouchneedle connected to the pouch and the skin needle deflected downwardsthrough the bottom of the patch and into the user's skin.

FIGS. 8A and 8B illustrate selection of the size, shape, or othercharacteristics of the fluid channel in the needle sled to control thetime or rate of medication delivery.

FIGS. 9A and 9B show a curved channel that deflects the skin needle sothat it exits the bottom of the patch and enters the skin at an angle;FIG. 9A shows an exploded view of two halves of the channel, and FIG. 9Bshows these two halves together to form the curved channel.

FIG. 10A shows an exploded view of the medication pouch with the capassembly removed to show a fluid channel covered by a dual septum. FIG.10B shows a side section view of the pouch needle piercing the dualseptum from the side and of a fill needle piercing the dual septum fromthe bottom.

FIG. 11A illustrates the wedge at its end-of-delivery position where itbegins to push the needle sled backwards. FIG. 11B shows the needle sledfully retracted when the wedge reaches its end-of-travel position.

FIGS. 12A and 12B show an illustrative embodiment with a needle sledpush carriage that pushes the needle sled forward and then decouplesfrom the needle sled; FIG. 12A shows an exploded view from the top, andFIG. 12B shows a view from the bottom to show how the push carriagelocks into the needle sled.

FIG. 13 illustrates how the push carriage embodiment of FIGS. 12A and12B unlocks from the needle sled when the needle sled is deployed.

FIG. 14 shows an architectural block diagram showing selected componentsof an illustrative patch and relationships among the components.

DETAILED DESCRIPTION OF THE INVENTION

A mechanically driven medication delivery patch will now be described.In the following description, numerous specific details are set forth inorder to provide a more thorough understanding of embodiments of theinvention. It will be apparent, however, to an artisan of ordinary skillthat the present invention may be practiced without incorporating allaspects of the specific details described herein. In other instances,specific features, quantities, or measurements well known to those ofordinary skill in the art have not been described in detail so as not toobscure the invention. Readers should note that although examples of theinvention are set forth herein, the claims, and the full scope of anyequivalents, are what define the metes and bounds of the invention.

FIGS. 1A, 1B, and 1C show top and bottom views of an illustrativeembodiment of the medication delivery patch 100. The patch contains aninternal pouch (not visible) between the top cover and the bottomsurface that may be filled with a medication or other fluid. One or moreembodiments may use the patch for delivery of any type of drug,nutrient, medical fluid, vitamin, supplement, nutraceutical, or anyother fluid or gel or solution to the body of a user. The characteristicof the fluid includes aqueous, oily, emulsions, micro or nanosuspensions, gels depending on needle gauge wherein the fluid includes awide viscosity range 0.5 centipoise to 200 centipoise. The user may befor example a human or an animal. The embodiment 100 is entirelymechanically driven: it contains no electronics or electrical parts andrequires no source of electrical power. Most of the components of patch100 are not visible in FIGS. 1A, 1B, and 1C; these components areillustrated in other figures and described below.

The top side of 100 shown in FIG. 1A illustrates a top cover 101, withan activation button on the top side that is initially covered with asafety cover 111. (The activation button 102 is shown in FIG. 1B). Thesafety cover 111 prevents a user from accidentally pressing theactivation button. A pull ring 112 (or similar element) may be connectedto safety cover 111. To use the patch, a user (or someone assisting theuser) may first remove safety cover 111 to expose activation button 102,as shown in FIG. 1B; this person may then start the delivery of thepatch contents by pressing the activation button 102. As describedbelow, pressing this button initiates a chain of events that result inthe pressurization of the medication pouch, the puncturing of the pouchseptum, the emergence of a needle from the bottom of the pouch, and flowof the contained fluid into the user. The embodiment 100 also has one ormore clear windows 103 in the top cover 100 that will display anindicator when the delivery of the patch contents is complete, and theneedle has been retracted from the user. The activation button 102 isaccessible through top cover 101. In one or more embodiments anactivation button or a similar activation input may be located anywhereon the patch that is accessible to the user. The button area is sealedto the outside to prevent ingress of liquid or microbes. There may befor example a seal around the button and an elastomeric coating coveringall connecting points of the different pieces. One or more embodimentsof the invention include a secure seal between top cover 101 and bottomsurface 104 to maintain the sterility of the needles held within.

FIG. 1C shows the bottom side of patch 100. The bottom surface 104 ofthe patch may for example be placed against the skin of the user orcoupled to the user's body in some manner. This surface may be adhesivefor example; it may be covered by a protective film or other coveringsurface that is first removed before the patch is applied to the skin.The strength of the adhesive may be selected based on the expectedlength of time the patch will be applied to the skin; a longer durationdelivery may require a stronger adhesive. Bottom surface 104 has anindentation 105 through which the needle emerges to pierce the skin, asdescribed below. The bottom surface also has a port 106 through whichthe patch may be filled, as described below. These holes 105 and 106 maybe covered with a film to ensure that the internal region of the patchis sealed. The needle that emerges to pierce the skin may pierce thisfilm as it exits the patch through hole 105, and a needle for fillingmay pierce the film to enter the interior of the patch through hole 106.One or more embodiments enable a duration of delivery between 5 secondsand 7 days. Embodiments of the invention deliver medications thatinclude bioactive molecules or substances, peptides, proteins, smallmolecules, vaccines, vitamins, minerals, biocompatible fluids.

FIG. 2 shows an illustrative use case for the patch 100. A protectivefilm or surface covering the bottom surface of the patch may be firstremoved, for example to expose an adhesive surface that sticks to theskin. A user or caregiver then places the patch 100 on the skin 201,which may be anywhere on the body. One or more embodiments may beutilized on the abdomen, thighs and arm or forearm as shown. FIG. 2shows placement on an arm; one or more embodiments may be configured forexample to be placed on the front abdomen, or any other portion of thebody that facilitates delivery of the medication enclosed in the patch.The user or caregiver then removes the protective cover 111 and pressesthe activation button 102, which sets in motion a chain of events thatresults in a skin needle 202 protruding from the bottom surface of thepatch and piercing the skin 201, and results in a flow of the fluid 203contained in the patch from the pouch in the patch through the skinneedle 202 and into the user. Fluid 203 may be any medication or othersolution or gel or fluid that is to be delivered to or through the skinof the user.

We now describe illustrative internal components of one or moreembodiments of the invention, and the events and actions that causedelivery of the fluid and then retraction of the needles when deliveryis complete. In the embodiments shown, all components and linkages aremechanically driven, for example using stored mechanical energy insprings or similar energy storage devices. These embodiments have noelectrical or electronic components, so may lower cost, improvereliability, and may make the patch more robust. One or more embodimentsmay modify these components and linkages as desired to achieve the sameeffects of fluid delivery upon activation, followed by needle retractionwhen delivery is complete.

FIG. 3 shows patch 100 with the top cover and activation button removed.The internal components are shown in their state before activation.(Some internal components are largely or completely hidden in thisview.) A pouch 301, which may be made of a flexible or compressiblematerial, contains the fluid to be delivered. This pouch may be ofcompatible size, shape, and material. One or more embodiments of pouch301 may enable a volume of fluid between 0.3 to 50 mL. The pouch canwithstand up to 82 psi in one or more embodiments, while typicalpressure within the pouch when filled may be 2 to 7 psi for aqueousfluids. A plate 331 may lie on top of the pouch. A wedge 302, whichstarts at an initial position at the edge of the pouch, is forcedagainst the plate after activation, in this embodiment by wedge springs304 a and 304 b, or by a similar wedge force element, applying pressureto the fluid contained in the pouch to cause delivery of the fluidthrough the needles described below. (In the view of FIG. 3, the springsare largely below the wedge, so they are shown in dotted lines.) Thewedge 302 is shown in FIG. 3 with diagonal hatching for clarity. Wedge302 includes integral or attached “arms” 305 a and 305 b that extendtowards the left side (in FIG. 3) of the patch; these arms move with thewedge and they activate or retract other components as described below.Prior to activation, the wedge 302 is held in its initial position by awedge latch 303; this latch is released when the activation button ispressed. Embodiments of pouch 301 may be made from biocompatiblepolymers or polymer laminates or blends of polymers with one or moreembodiments providing a clear flexible wall for the pouch. Thesepolymers utilized for pouch 301 include commonly used polymers forinjectable products, such as, but not limited to polyethylene,polypropylene, COP, COC, PCTFE, EVOH, polyurethane.

When the wedge 302 starts moving, the arm 305 a of the wedge (or asimilar element integrated into or coupled to the wedge) initially movesforward a slight amount to allow rotation which then rotates a pivotingsled release element 306 (shown cross-hatched in FIG. 3) to releaselatch 306 a that holds in place a needle sled 307. This needle sled maybe any type of element or elements that move needles to cause deliveryof the fluid in the pouch to the user. For clarity the needle sled 307is shown in FIG. 3 with diagonal hatching. After the release of latch306 a the needle sled 307 is driven forward by a spring 308, or similarneedle sled force element, moving it from the retracted position (asshown in FIG. 3) to a deployed position to deliver the fluid to theuser. The illustrative needle sled 307 contains or is coupled to twoneedles. Skin needle 202 will exit the bottom of the patch through hole105 to pierce the user's skin. Pouch needle 311 will enter a fluidchannel coupled to the pouch through a cap assembly 313, to allow thefluid in the pouch to flow from the pouch into the pouch needle. Needlesled 307 also has a fluid channel 320 that connects the interior of thepouch needle 311 to the interior of the skin needle 202 to complete thefluid flow path from the pouch into the user. The channel 320 may becovered by a hydrophobic membrane that allows air to vent to atmosphereat the beginning of the delivery cycle. When the vent is fully wetted itseals against the fluid completing the fluid pathway. The skin needle202 may be deflected through a curved channel or similar feature so thatit enters the skin at an angle when it protrudes from the bottom of thepatch (through a film that seals the hole); FIG. 3 shows a bottomportion 316 b of a needle guide element with this curved channel.Initially, when retracted, the skin needle 202 may be for exampleroughly horizontal (roughly parallel to the user's skin when the patchis applied).

Illustrative gauges for the pouch needle 311 in one or more embodimentsmay be for example in the range of 18 gauge to 27 gauge; illustrativegauges for the skin needle 202 may be for example in range of 25 gaugeto 34 gauge. The skin needle 202 may have varying lengths in variousembodiments, to achieve the desired depth of entry into the skin orthrough the skin. For intradermal injections, illustrative skin needlelengths may be for example in the range of 3 mm to 5 mm; forsubcutaneous injections, illustrative skin needle lengths may be forexample in the range of 12 mm to 16 mm. The angle of insertion forintradermal injections may be between 5 and 15 degrees inclusive, whilethe angle of insertion for subcutaneous insertion may be 45 to 90degrees in one or more embodiments.

After delivery of the fluid in the pouch to the user is complete, theskin needle 202 may be retracted from the user into the interior of thepatch (for safety and to facilitate patch removal), and the pouch needle311 may be retracted from the septum covering the fluid channelconnected to the pouch (for example to prevent any residual fluid fromleaking and to ensure delivery of a precise amount of the fluid to theuser). In embodiment 100, these needle retractions are achieved bypushing the needle sled 307 backwards (towards its retracted position)when delivery is complete. The pushing of the needle sled backwards maybe performed by the wedge arm 305 b, which contacts corresponding arm319 of the needle sled when the sled is deployed and the wedge has movedacross the plate 331 to an end-of-delivery position where medicationdelivery stops and needle retraction begins. Motion of the wedge 302therefore may provide multiple functions of releasing needle sled latch306 a upon activation, forcing the fluid out of pouch 301 for delivery,and retracting the needle sled 320 (and the needles 311 and 202) afterdelivery.

A delivery complete indicator 309 is integrated into or attached towedge 302. When the wedge is at the end-of-travel position, where it isat the limit of its motion (leftwards in FIG. 3), this indicator ispositioned directly below the window 103 in the top cover. Appearance ofthis indicator in the window shows the user that the delivery iscomplete and the needles are retracted, and that the patch can beremoved. The indicator may for example be of a distinctive color (suchas red or yellow), shape, or pattern for easy recognition. One or moreembodiments may put one or more visible indicators in any area of thepatch, including but not limited to the top of the patch cover. Forexample, an indicator may be visible through a side of the patch ratherthan (or in addition to) through the top cover. In one or moreembodiments, one or more indicators may show the progress of medicationdelivery in addition to an indication that the process is complete, forexample along the side of one or more embodiments of medication deliverypatch 100.

FIG. 4A shows a view of the wedge 302, the plate 331, and the pouch 301.A port 401 is attached to an opening in pouch 301; this port has dualopenings 402 a (for the pouch needle) and 402 b (for filling) asdescribed below. As springs 304 a and 304 b force the wedge forward, thesloped surface of the wedge 302 presses downward on plate 331, which inturn presses on pouch 301. The plate, and the wedge surface or surfacesthat contact the plate may be of any compatible size and shape. In oneor more embodiments, the wedge or similar element may push directly onthe pouch, rather than on a plate that in turn presses on the pouch. Inone or more embodiments the wedge or other element that applies pressuremay travel along any surface of the pouch, including the top, bottom, orside of the pouch. In one or more embodiments, the wedge may not travelacross the pouch, but instead may push against any surface of the patchto apply pressure; for example, the wedge may be forced against the topor bottom surface of the pouch when it is released. The plate may have acompressible foam or membrane between it and the pouch to aide in fullyevacuating the pouch.

In one or more embodiments of the invention, force generating element(s)may be integrated into the wedge element; side views of illustrativeexamples are shown in FIGS. 4B and 4C. In the wedge embodiment 302 ashown in FIG. 4B, the wedge has a lower section 411 that presses on thepouch; this section 411 is coupled to an upper wedge section 413 by aspring or similar force element 412. Sections 411 and 413 may be coupledby a pivot joint for example. In embodiment 302 b shown in FIG. 4C, theforce of spring 412 is replaced by resistance of a portion 422 of thewedge that joins the upper section 423 and lower section 421; forexample, this portion 422 may be made of a flexible but relatively stiffmaterial.

FIG. 5 shows an illustrative mechanism for activating the delivery offluid from the pouch. Activation button 102 is shown in an exploded viewabove the patch case and is shown as a wireframe to illustrate itsinternal shape. Latch 303 holds portions 501 a and 501 b of wedge 302 inplace prior to activation, resisting the movement of the wedge. Whenbutton 102 is pushed down, protrusion 102 a below the button pressesdown on latch 303 and these the portions 501 a and 501 b can move overthe top of the latch, releasing the wedge to move forward from the forceprovided by springs 304 a and 304 b. One or more embodiments may couplethe activation button or similar activation element to the wedge latchor latches in any desired manner. The button may have one or moreprotrusions or extensions that contact or otherwise release any latch orlatches. The activation button protrudes through the top cover of thepatch and may be surrounded by a seal (such as a silicone gasket) thatseals the gap around the edge of the button between the button and thetop cover. These features may be configured to require sufficient forcefor activation such that the device will not accidentally fire due toshock or vibration.

When wedge 302 moves forward after activation, it first moves to unlockthe rotating release mechanism and then forces 306 to rotate therebyreleasing the needle sled 307 so that the attached needles can piercethe skin and the pouch septum to initiate delivery of fluid to the user.FIGS. 6A, 6B, and 6C show an illustrative mechanism for release of theneedle sled. FIGS. 6A and 6B show the needle sled 307 prior toactivation. The needle sled is held in place by a needle sled latch 306a that is coupled to pivoting needle sled release element 306. This sledrelease element 306 acts as a linkage between the arm 305 a of the wedgeand the latch 306 a. This release element 306 is shown cross-hatched inFIGS. 6A through 6C for clarity. Needle sled release element 306 isconstrained to move only by pivoting around its longitudinal axis. FIG.6B shows a cylindrical extension 306 b at one end of element 306, whichfits into a corresponding cylindrical pocket; a similar feature is onthe other end of element 306. These two cylindrical extensions supportthe release element 306 and allow it to rotate. Latch 306 a initiallycovers a part of the front face of needle sled 307, preventing theneedle sled from moving forward. This portion of the needle sled thatcontacts the latch 306 a is not visible in FIGS. 6A and 6B, but isvisible as region 307 a in FIG. 6C where the needle sled release element306 has rotated to release the needle sled. FIG. 6B shows that theneedle sled release element 306 is locked to the wedge arm 305 a inregion 601, which prevents the release element 306 from rotating priorto activation. This locking prevents the needle sled from beingunlatched accidentally due to shock or vibration. When the wedge isreleased by the activation button, it moves forward so that the needlesled release element 306 is no longer locked to the wedge arm. The tipof wedge arm 305 a presses on the corresponding tip of the releaseelement 306, causing it to rotate and raise latch 306 a, as shown inFIG. 6C; this allows the needle sled to move forward.

The pivoting release mechanism shown in FIGS. 6A through 6C is anillustrative mechanism to release the needle sled as a result of theforward motion of the wedge. One or more embodiments may use other typesof linkages and latches to link the wedge motion to the release of theneedle sled. In one or more embodiments the activation button or similaractivation input may directly release a needle sled latch, instead ofusing the wedge motion to release the needle sled latch.

FIGS. 7A and 7B show needle sled 307 before and after it has movedforward to insert needles, respectively. In FIG. 7A, with the needlesled in its retracted position before activation, pouch needle 311 ispositioned opposite a conduit or aperture 701 that leads to a septumcovering the fluid pouch fluid path, and skin needle 202 is positionednear hole 105 in the bottom of the patch case. FIG. 7B shows sled 307after it moves forward to its deployed position under the force fromneedle sled spring 308. Pouch needle 311 has pierced the septum coveringthe pouch fluid path. The skin needle 202 is deflected downwards throughhole 105 and through a film covering the hole and it enters the skin.Fluid 203 then flows from the pouch 301 to the pouch needle 311, throughthe fluid channel 320 in the needle sled, through the skin needle 202,and into the user.

In one or more embodiments of the invention, one or more components ofthe patch may be configured or selected to control the rate of fluiddelivery or the total time of fluid delivery (or both). Time of deliverymay be measured for example between a start time when the activationbutton is pressed, and an end time when the wedge reaches itsend-of-travel position. This feature allows the patch to be configuredfor different medications and use cases, or to adapt to differentpatient needs or prescriptions. One component that may be used tocontrol the rate or time of delivery is the fluid channel 320 in theneedle sled 307 that connects the pouch needle 311 and the skin needle202. The diameter, length, shape, materials, valves, flow restrictors,or other features of this fluid channel may be modified to affectdelivery speed and time. This channel may for example include amicrofluidic channel. In one or more embodiments the features of thechannel may include valves or flow restrictors to modify the rate offlow through the channel. For example, FIG. 8A shows an illustrativeembodiment with a fluid channel 320 a that is selected for rapiddelivery time 801 a. FIG. 8B shows an illustrative embodiment with afluid channel 320 b that is selected for much longer delivery time 801b. Channel 320 b may for example be longer, narrower, and it may containone or more valves or flow restrictors 802 that affect the flow ratethrough the channel. Illustrative fluid delivery times in one or moreembodiments may range for example from 10 seconds to 7 days.

FIGS. 9A and 9B illustrate a curved channel that deflects skin needle202 downwards so that it passes through the bottom cover of the patchand enters the user's skin at an angle. FIG. 9A shows a cutaway view ofone half of the top cover 101 and a corresponding half of the bottomcover 104; these parts are shown exploded from one another. Integratedinto or coupled to the bottom cover is the bottom portion 316 b of aneedle guide element with a curved upper surface, and integrated into orcoupled to the top cover is the corresponding top portion 316 a of theneedle guide element with a mating curved surface. In this illustrativeembodiment, the curved needle channel is formed between these twoelements 316 a and 316 b. FIG. 9B shows a cutaway view through thecenter of the joined elements 316 a and 316 b, showing the curvedchannel formed between these elements through which skin needle 202passes and is deflected through hole 105 in the bottom housing 104. Oneor more embodiments may use any element or combination of elements todeflect or guide the skin needle through any channel or aperture to exitthe patch and to enter the user's skin. The deflection amount of theskin needle may be varied in various embodiments; typical values for theangle at which the skin needle enters the skin may be for examplebetween 30 degrees and 90 degrees.

FIG. 10A shows an exploded view of pouch 301 elevated from the bottomhousing 104, with the cap assembly 313 removed to show a dual septum1001 that covers the ports 402 a and 402 b into the fluid conduit 401connected to the pouch. Cap 313 holds dual septum 1001 in place when itis installed. The dual septum contains two different regions that werefer to as the pouch septum and the fill septum. The side-facingportion of dual septum 1001 is the pouch septum 1001 a that is acrossfrom pouch needle 311; the pouch needle 311 pierces this pouch septumportion 1001 a of the dual septum 1001 when the needle sled movesforward. The bottom portion of dual septum 1001 is the fill septum 1001b that is above fill hole 106 in the bottom housing 104; this fillseptum may be used for filling the pouch. FIG. 10B shows a side view ofpouch 301 and dual septum 1001. A pharmacist or other supplier maypierce the fill septum with a syringe 1002 or similar filling deviceinserted through hole 106 to fill the pouch 301 with fluid beforedelivering it to the user. This feature may allow providers to stockembodiments of the invention and then fill them with desired fluids ondemand. In one or more embodiments, a fill port may not be provided andthe pouch 301 may be prefilled; for example the pouch may be factoryfilled during patch assembly. If the pouch is pre-filled, fill septum1001 b and fill hole 106 may not be included in one or more embodiments.

After delivery of the desired amount of fluid in the pouch to the user,one or more embodiments of the patch may retract the needles from theskin and the pouch to stop fluid flow and allow the user to remove thepatch. FIGS. 11A and 11B illustrate a method that may be used to retractthe needles in one or more embodiments. FIG. 11A shows needle sled 307in the deployed position, with the skin needle and pouch needle in theuser's skin and in the pouch septum, respectively. When wedge 302completes its travel across the plate and arrives at its end-of-deliveryposition (as shown in FIG. 11A), wedge arm 305 b contacts correspondingarm 319 of needle sled 307. As shown in FIG. 11B, the wedge continues totravel forward to its end-of-travel position and pushes the needle sled307 back towards its initial (retracted) position, retracting theneedles 311 and 202. FIG. 11A also shows indicator 309 on the wedge andwindow 103 of the top cover. As the wedge moves forward to theend-of-travel position shown in FIG. 11B, the indicator 309 on the wedgereaches its final position under the window 103, indicating to the userthat the process is complete, and the patch can be removed.

One or more embodiments of the invention may incorporate a mechanism todecouple the needle sled 307 from the needle sled spring 308 (or similarforce element) after the needle sled is deployed. This decoupling mayfacilitate the retraction of the needle sled using the force applied bythe wedge, as shown in FIGS. 11A and 11B. Although the wedge springs maybe selected to be sufficiently strong to overcome the force of theneedle sled spring, decoupling the needle sled spring may reduce size,weight, and cost by reducing the size and strength required from thewedge springs. FIGS. 12A, 12B, and 13 show an illustrative mechanismthat may be used to provide this needle sled spring decoupling in one ormore embodiments. In this illustrative mechanism, the needle sled is notpushed directly by the needle sled spring; instead, as shown in FIG. 12Ain an exploded view and in FIG. 12B as an integrated view from below,the needle sled spring is coupled to a needle sled push carriage 1201.This push carriage 1201 is in turn detachably latched into needle sled307. Push carriage 1201 has flexible arms 1201 a and 1201 b withprotrusions that fit into mating indentations 1202 a and 1202 b in theneedle sled, as shown in the view from below in FIG. 12B. When pushcarriage 1201 is latched into the needle sled 307, the force from spring308 is transmitted to the needle sled, moving the needle sled forward toits deployed position. As shown in FIG. 12A, integrated into or coupledto the bottom housing of the patch are two sloped carriage releaseelements 1203 a and 1203 b. These sloped elements press against arms1201 a and 1201 b when the push carriage 1201 reaches the end of itsforward travel. The arms 1201 a and 1201 b are then pinched inward,releasing them from the indentations 1202 a and 1202 b on the needlesled, and thereby unlatching the needle sled from the push carriage.This action is shown in FIG. 13, which shows push carriage 1201 in itsdeployed (fully forward position). The ends of the needle sled are shownin dotted lines to illustrate the position of the indentations 1202 aand 1202 b; because arms 1201 a and 1201 b are pinched inwards, theneedle sled is decoupled from the push carriage at this point.Therefore, the wedge can push the needle sled backwards, retracting theneedles, without having to overcome the force of the needle sled spring308.

The specific sizes, shapes, and arrangements of the patch componentsdescribed above are illustrative; one or more embodiments may use othercomponents with different shapes or sizes that are arranged in differentconfigurations. FIG. 14 shows a block diagram view of one or moreembodiments of the invention that describes functional relationshipsamong illustrative components that are independent of components' sizes,shapes, positions, and orientations. One or more embodiments of theinvention may use a subset of these components; for example, asdescribed above, a release mechanism for a needle sled push carriage maynot be needed if the force applied to the wedge is sufficient toovercome the force of the needle sled spring or similar force element.

As shown in FIG. 14, in one or more embodiments an activation input 102,such as a button, lever, switch, or other control, is activated torelease a wedge latch 303 that holds a wedge 302 in its initialposition. The wedge latch 303 may be any element that applies a force tohold the wedge into position. The wedge 302 may be any element that canapply pressure, either directly or indirectly, to pouch 301 containingthe fluid to be delivered. When wedge latch 303 is released, one or morewedge force elements 304 push (or pull or otherwise move) wedge 302. Asor shortly after wedge 302 begins to move, it (directly or indirectly)releases a needle sled latch 306 a, which holds needle sled 307 in itsretracted position. The needle sled force element(s) 308 then pushforward the needle sled 307 to its deployed position. In one or moreembodiments the needle sled may be pushed forward indirectly via aneedle sled push carriage 1201. The needle sled 307 is coupled to orintegrated with pouch needle 311 and skin needle 202, and it connectsthese two needles via a fluid path 320. As the needle sled moves forwardto its deployed position, pouch needle 311 connects a fluid path topouch 301, and skin needle 202 connects this fluid path to the user 201.The skin needle 202 may be deflected by a curved channel 316 a and 316 bto enter the user's skin at a desired angle. As the wedge moves forward,the applied pressure to the pouch 301 from wedge 302 causes fluid toflow from the pouch 301 through the pouch needle 311, through the path320 in the needle sled 307, through the skin needle 202, and into user201. As the wedge reaches an end-of-delivery position, it contacts andpushes backward on needle sled 307, causing retraction of the needles asthe needle sled is pushed back to its retracted position. In one or moreembodiments with a needle sled push carriage 1201, as the needle sled307 reaches its deployed position, one or more carriage release elements1203 a/1203 b may release the needle sled push carriage 1201 from theneedle sled 307, facilitating retraction of the sled. At the end of itstravel, wedge 302 moves delivery complete indicator 309 into view forthe user to indicate completion of the fluid delivery and completion ofneedle retraction.

While the invention herein disclosed has been described by means ofspecific embodiments and applications thereof, modifications andvariations could be made thereto by those skilled in the art withoutdeparting from the scope of the invention set forth in the claims.

What is claimed is:
 1. A mechanically driven medication delivery patch,comprising: a bottom surface of a patch, said bottom surface configuredto be coupled to skin of a user; a top cover of said patch; a pouchconfigured to contain a fluid to be delivered to said user, said pouchsituated between said bottom surface and said top cover; an activationbutton; a wedge configured to move from an initial position to anend-of-delivery position, and from said end-of-delivery position to anend-of-travel position, and configured to apply pressure to said fluidbetween said initial position and said end-of-delivery position; a wedgeforce element configured to apply force to said wedge to cause saidwedge to move; a wedge latch that holds said wedge in said initialposition prior to activation; a needle sled comprising a pouch needleconfigured to penetrate a pouch septum in contact with said fluid; askin needle configured to penetrate said skin of said user; and a fluidchannel coupling an interior of said pouch needle and an interior ofsaid skin needle; wherein said needle sled is configured to move betweena retracted position and a deployed position; a needle sled forceelement configured to apply force to said needle sled to cause movementof said needle sled to said deployed position and to cause  said pouchneedle to penetrate said pouch septum;  said skin needle to penetratesaid skin of said user; and  said fluid to flow from said pouch throughsaid pouch needle, through said fluid channel, and through said skinneedle into said user; a needle sled latch that holds said needle sledin said retracted position; wherein when said activation button ispressed, said wedge latch is released, allowing said wedge to move fromsaid initial position, and said needle sled latch is released, allowingsaid needle sled to move to said deployed position; and when said wedgereaches said end-of-delivery position, said wedge applies force to saidneedle sled to move said needle sled towards said retracted position,and to retract said pouch needle from said pouch septum; and retractsaid skin needle from said skin of said user and into an interior ofsaid patch.
 2. The mechanically driven medication delivery patch ofclaim 1, wherein said patch contains no electronic components.
 3. Themechanically driven medication delivery patch of claim 1, wherein saidpouch comprises a flexible material.
 4. The mechanically drivenmedication delivery patch of claim 1, further comprising a plate betweensaid wedge and said pouch; wherein said wedge applies force to saidplate and said plate transfers said force to said pouch to apply saidpressure to said fluid between said initial position and saidend-of-delivery position.
 5. The mechanically driven medication deliverypatch of claim 1, further comprising a fill port coupled by a fillchannel to said pouch; and, a fill septum closing said fill port andconfigured to be penetrated by a fill needle to fill said pouch withsaid fluid.
 6. The mechanically driven medication delivery patch ofclaim 1, further comprising a delivery complete indicator configured toprovide a visual indication that said wedge reaches said end-of-travelposition.
 7. The mechanically driven medication delivery patch of claim6, wherein said top cover comprises a window; said delivery completeindicator is coupled to or integrated into said wedge; said deliverycomplete indicator is visible through said window when said wedgereaches said end-of-travel position.
 8. The mechanically drivenmedication delivery patch of claim 1, wherein one or more of a shape,length, diameter, materials, valves, and flow restrictors of said fluidchannel are configured to provide a desired rate of delivery of saidfluid to said user over a desired time period between a start time whensaid activation button is pressed and a finish time when said wedgereaches said end-of-travel position.
 9. The mechanically drivenmedication delivery patch of claim 8, wherein said fluid channelcomprises a microfluidic channel.
 10. The mechanically driven medicationdelivery patch of claim 8, wherein said one or more of a shape, length,diameter, materials, valves, and flow restrictors of said fluid channelare configured to select said desired time period in a range between 10seconds and 7 days.
 11. The mechanically driven medication deliverypatch of claim 1, wherein said wedge force element comprises one or morewedge springs; and, said needle sled force element comprises one or moreneedle sled springs.
 12. The mechanically driven medication deliverypatch of claim 1, wherein said activation button comprises one or moreactivation button extensions extending into an interior of said patchand configured to contact said wedge latch when said activation buttonis pressed and to apply force to said wedge latch to release said wedgelatch.
 13. The mechanically driven medication delivery patch of claim 1,wherein said wedge is configured to contact a needle sled releaseelement coupled to said needle sled latch, and transmit a portion ofsaid force applied by said wedge force element to said needle sledrelease element to release said needle sled latch.
 14. The mechanicallydriven medication delivery patch of claim 13, wherein when said wedgecontacts said needle sled release element, said needle sled releaseelement pivots to release said needle sled latch.
 15. The mechanicallydriven medication delivery patch of claim 1, further comprising a needlesled push carriage coupled to said needle sled force element andreleasably coupled to said needle sled, and configured to transmit forcefrom said needle sled force element to said needle sled.
 16. Themechanically driven medication delivery patch of claim 15, wherein saidneedle sled push carriage is configured to detach from said needle sledwhen said needle sled reaches said deployed position.
 17. Themechanically driven medication delivery patch of claim 16, furthercomprising one or more carriage release elements configured to contactone or more portions of said needle sled push carriage when said needlesled reaches said deployed position and to decouple said needle sledpush carriage from said needle sled.
 18. The mechanically drivenmedication delivery patch of claim 1, wherein a gauge of said pouchneedle is in a range between 18 gauge and 27 gauge; and, a gauge of saidskin needle is in a range between 25 gauge and 34 gauge.
 19. Themechanically driven medication delivery patch of claim 1, furthercomprising a curved channel through which said skin needle travels whensaid needle sled moves from said retracted position to said deployedposition, causing said skin needle to change orientation fromsubstantially parallel to said skin of said user in said retractedposition to non-parallel with said skin of said user in said deployedposition.
 20. The mechanically driven medication delivery patch of claim19, wherein when said needle sled is in said deployed position, an anglebetween said skin needle and said skin of said user is greater than orequal to 30 degrees and less than 90 degrees.